Lab Test

HER2 Gene Amplification Assay by FISH

C-erb B-2, HER2 FISH, PathVysion, HER2 Amplification Test (FISH), FISH for Breast Cancer , SOFT LAB: MPATG, SOFT GENE: MPATH

Specimen Collection Criteria

Collect (preferred specimen): Formalin-fixed, paraffin-embedded block with corresponding H&E slide. Tissue shold be well fixed and well processed. Tissue size should be 0.2 cm x 0.2 cm x 0.2 cm.
Also acceptable: One H&E slide plus 3 unstained tissue sections cut at 4.0 um thick and placed on charged slides. Oven dry at 60°C for 1 hour. Unbaked or air-dried slides are acceptable. Tissue adherence cannot be guaranteed for sections placed on plain glass slides. Send all slides within 6 weeks of cutting.

Specimen must be accompanied by a completed requisition and must contain the patient name, date of birth, collection date, ordering physician, and source of specimen. Provide pathology report with each specimen, including type of fixative and duration of fixation (if known).

Physician Office/Drawsite Specimen Preparation

Maintain paraffin-embedded tissue or slides at room temperature (20-25°C or 68-77°F) until transport.

Preparation for Courier Transport

Transport: Paraffin-embedded tissue or slides, at room temperature (20-26°C or 68-78.8°F).

Rejection Criteria

  • Tissue in fixatives other than 10% formalin.
  • Improper labeling, inadequate information.
  • Decalcified specimens.


Twice weekly.
Results available in 5-7 days.

Reference Range

0 - 30x gene amplification.

Test Methodology

Fluorescent in situ Hybridization.


Hybridized sections are reviewed on a fluorescence microscope by a trained Molecular Technologist. The percent amplification is determined using a computer assisted algorithm. Results are reviewed by the pathologist who will provide an interpretive report. Results are reported as Not Amplified (HER2/CEP17 ratio less than 2.0 and average HER2 copy number less than 4.0 signals/cell), Amplified (HER2/CEP17 ratio greater than or equal to 2.0 or average HER2 copy number greater than or equal to 6.0 signals/cell), or Equivocal (HER2/CEP17 ratio less than 2.0 and average HER2 copy number less than 6.0 and greater than or equal to 4.0 signals/cell).

Clinical Utility

HER2 gene amplification has been associated with a shorter disease-free interval and shorter overall survival. Women who have tumors with HER2 gene amplification are most likely to be responsive to monoclonal antibody therapy directed against this target.


  1. Wolff AC, Hammond MEH, Hicks DG, et al. American Society of Clinical Oncology/College of American Pathologists Guideline Recommendations for Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer. J Clin Oncol 2013 Nov 1; 31(31) 3997-4013.

CPT Code

88366, 88374 (Automated).

Test Codes


Last Updated


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This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.